The invention concerns a wheel for air or gas filled tires for motor vehicles, the central dish or disc of the wheel being enclosed in a ring-shaped rim.
Because wheels, axles and associated fittings constitute unsprung masses on vehicles, it is important for driving comfort and safety to keep the weight of these components as small as possible. Attempts to employ lightweight wheels has led to lightweight constructions, such as wheels with spokes, and also to the choice of lighter materials, resulting in cast or forged wheels made of alloys of aluminum or magnesium.
However, the cost of spoked wheels is too high. Also, it has been necessary in the case of light metal wheels to make the product more expensive than desired. This is due to the fact that in the case of light metal wheels the lower strength in comparison with steel, for example, and the greater susceptibility to crack formation in highly stressed parts of the light metal wheel, make it necessary to have thick sections there, thus making the product more expensive than desired and at the same time greatly diminishing the weight advantage gained using the light metal. The greater susceptibility to crack formation is particularly evident at the points of transition between the rim and the central disc, and also in the region of the adjacent flanges.